Silicon-based Traveling Wave-like Fabry–perot Resonator Photonic Devices

The development of microelectronics has greatly promoted the development of human production and living.With the requirements of transmission speed and bandwidth,traditional electrical interconnects are slowly not meeting the needs of development.Silicon-based photonics is widely used in optical chips,optical computing and optical fiber communications because of its high transmission bandwidth and low cost.The add-drop filter implements the key components of the wavelength division multiplexing system.The structure that realizes the performance is mainly micro-ring resonators and photonic crystals.As the micro-ring radius of the micro-ring resonator decreases,the bending loss in the ring increases and the coupling efficiency at drop port decreases.At the same time,the input port and output port of the micro-ring resonator are on the same side.For the cascade of 2×2 devices,the extra crossover increases the design complexity of the device and also increases the size of the overall resonant cavity.The structure of add-drop filter formed by the photonic crystal waveguide and the single cavity is not very efficient at the drop port.In order to increase the efficiency,the destructive interference increases to two cavities,which can improve the efficiency of drop port,but greatly increase the size of the device.In addition,the fabrication process of photonic crystals is complicated and the process repeatability is poor.Based on the above background,this paper will introduce a new type of add-drop filter based on a single Fabry-Pérot Resonator(F-P cavity).The new add-drop filter uses a single cavity and does not require an additional design to achieve light-wave propagation.It has the advantages of flexible design,small size,and low loss.The single F-P cavity consists of a straight waveguide and two mode mirrors.The size of the single F-P cavity is 34.5×1μm~2.The simulation results show that the reflection efficiency of the mode mirror is more than 95%and the bandwidth is 80nm.The simulation results of the add-drop filter is 93%in the drop port,and the quality factor Q reaches 1300.The add-drop filter produced by the process platform has a drop efficiency of 68%at drop port,and only 8%of the light remains at the through port.The quality factor Q value also reaches 1300 or more.In addition,the quality factor Q reaches 22,000 when the cavity length L to 600μm.